Show HN: Free SaaS churn and retention calculators

I built a small set of free SaaS churn tools this weekend after repeatedly needing to calculate churn and revenue churn for side projects.

You just enter a few numbers and the results update instantly. No signup required.

If people end up using them, the anonymised data could eventually become useful churn benchmarks for founders.

Would love feedback if the calculations look correct or if there are other SaaS metrics that would be useful.